I've been using Director for a very long time, and I still have problems building shockwave sites.
The problem sounds like you're running the code before the assets (cast member, pictures sounds etc) have fully downloaded.
When running off a local computer this isn't a problem - but over the internet it is!!!
If your total dcr file is not too large - say under 10 - 20MB (will only take a few minutes to download)
then you only need to create a small preloader program 'with director' to download your larger shockwave file, then you play it from cache memory.
publish your director presentation file as one large dcr file - (under the publish tab - tick include linked cast files and copy linked and dependent files)
save this dcr file to your ftp web site location. (no html file required)
Now create a preloader dcr & html file
You use the 'preloadnetthing' to download the larger dcr file into memory.
point it to the full path name of your .dcr file = "http://www.yourwebsite.com/yourfile.dcr"
and use 'netdone' to tell it's finished loading.
Next you use the 'gotonetmovie' to play the larger dcr
copy the preloader dcr & html files also to your web site
now run the preloader.html file from your web browser.
[ If it's a super large file, or a very complex program made up of many files etc - then you'll have to take a much more difficult path. ]
Have a look at the .dir files in your %Adobe Director 12%\Configuration\Publish Templates\Loader Movies\ folder for examples of preloaders
Although I have not been able to look into this fully yet I want to thank you for taking the time to reply.
I think the additional comment may be invaluable too - as a Director novice any extra help is greatly appreciated. I am suprised, considering the cost - there is no acyual Help menu in the program, it just refers you to the website where there is also hardly any information regarding Di.